Mattress border construction and method

ABSTRACT

A mattress border assembly and method for preparing foam rails for shipment prior to assembly to form a mattress border assembly are disclosed. Strips of double-faced, high strength acrylic adhesive tape are applied to at least portions of the end walls of two foam rails. The second adhesive surface of the tape is covered with a protective liner until the border is to be assembled. When assembled, the end walls of the two foam rails are adhered with the tape to side walls of two other foam rails to form a generally rectangular frame structure that comprises the mattress border assembly. Optionally, additional strips of double-faced, high strength acrylic adhesive tape are applied to portions of the top walls and portions of the bottom walls of the foam rails so that additional mattress components may be adhered thereto.

[0001] This invention relates to a mattress border construction formed from pre-assembled components held together with adhesive tape.

BACKGROUND OF THE INVENTION

[0002] Generally, mattresses are formed with a mattress central portion surrounded by a mattress border construction. The mattress central portion may comprise a series of coil springs connected together and encased in a quilted fabric. Alternatively, the mattress central portion may comprise polyurethane or latex foam layers or synthetic or natural fibers, optionally in combination with springs, and encased in quilted fabric. The central portion might also constitute an air mattress or water mattress or other body-supporting mattress structure.

[0003] Mattress border constructions stabilize the edge or border portion of the mattress. It is desirable to have a more firm or more rigid border portion surrounding a less firm, body-supporting mattress central portion. Mattress border constructions of various types have been disclosed in the prior art. U.S. Pat. No. 5,537,699 discloses a mattress border construction formed with a foam rail sleeve surrounding a plurality of springs arranged in a row. The foam rail sleeve defines a core into which the row of springs is inserted. The foam is slit along its length so that it may be opened to permit insertion of the row of springs. The slit is then sealed with a liquid adhesive or a hot melt adhesive. The mattress border construction forms a periphery around the mattress center section, and is joined to the mattress center section also with a liquid adhesive or a hot melt adhesive. The adhesive coats the foam strands and penetrates into the foam pores to securely bond the mattress border construction to the mattress center section. It has been found, however, that the liquid adhesive can be difficult to apply, and can create more need for substantially clean up of applicators and surrounding surfaces on which excess adhesive collects. In addition, liquid adhesive and hot melt adhesive cannot be pre-applied before the mattress border construction is delivered to a mattress fabricator.

[0004] U.S. Pat. No. 5,701,623 shows a composite mattress topper, as opposed to a complete mattress construction. The topper has a latex foam rubber core section surround by border sections of urethane foam. The border sections are attached to the core section with adhesive to create the finished topper. The adhesive is not shown as able to be pre-applied before the component parts are shipped for later assembly.

[0005] A mattress assembly shown in U.S. Pat. No. 5,953,779 has a stack of foam mattress elements positioned one atop the other and joined together at their peripheral edges with hook and loop fasteners (VELCRO®). The fasteners keep the foam mattress elements aligned in stacked relation, but are intended to be removably separated and reassembled. The mattress so formed does not have a mattress border construction, and a retainer rope is secured around the outer edge of the mattress to hold the elements together. Additional holding support is provided by containment blocks optionally attached with VELCRO® to the head and foot of the mattress assembly.

[0006] U.S. Pat. No. 2,326,441 shows a mattress covering in which strips of fabric are secured to the sidewall of a foam sponge rubber mattress core with an adhesive. The fabric strips form an anchor onto which the mattress covering material may be stitched. No mattress border construction is provided around the sponge rubber mattress core.

SUMMARY OF THE INVENTION

[0007] A border assembly for a mattress or bedding material according to the invention has at least a first foam rail having a top wall, a bottom wall, a side wall and an end wall, and a second foam rail having a top wall, a bottom wall, a side wall and an end wall. A strip or piece of double-faced, high strength adhesive tape is applied to at least a portion of the end wall of the first foam rail so that said end wall may be fixedly adhered with said adhesive tape to at least a portion of the side wall of the second foam rail sleeve.

[0008] Preferably, the adhesive tape is an acrylic adhesive tape with a thickness of 0.002 inch to 0.010 inch. A suitable width and length of the tape may be selected depending upon the specific to application. To ensure secure bonding to foam, the adhesive tape preferably has from 30 to 34 grains of adhesive per 24 square inches, most preferably 32 grains of adhesive per 24 square inches. The target bonding strength is from about 5 to 15 psi, preferably about 10 psi. The adhesive tape should set and bond relatively quickly, such that it reaches about 90% of full bonding capability within about 10 minutes.

[0009] Preferably, the first foam rail has a second end wall and a second piece of adhesive tape is applied to at least a portion of the second end wall so that the first foam rail may be fixedly attached to at least a portion of the side walls of each of the second foam rail and another foam rail.

[0010] In the most preferred embodiment, the mattress border assembly comprises a series of four foam rails, with the first and third foam rails having double-sided adhesive tape applied to each end wall so that the first and third foam rails may be fixedly attached to at least a portion of the side walls of the second and fourth foam rails to form a generally rectangular frame. The double-sided tape preferably is applied to the end walls of the first and third foam rails by the foam fabricator prior to shipment to the mattress assembler. The side of the adhesive tape not adhered to the end walls is covered with a protective liner that may be removed when the border assembly is assembled by the mattress assembler.

[0011] In a most preferred embodiment, strips of double-faced adhesive tape are applied to at least a portion of each of the top and bottom walls of each of the first, second, third and fourth foam rails. The tape may be applied to the foam rails by the foam fabricator prior to shipment to the mattress assembler. When so applied, the adhesive surface not applied to the walls of the foam rails is covered with a protective liner that may be removed when the border is assembled by the mattress assembler. The adhesive tape on the top and bottom walls of the foam rails fixedly adheres the rails to other components of the mattress construction. In one such construction, sheets of foam are applied to cover the top and bottom walls and encase the mattress construction (such as springs) within the enclosed space defined by the foam rails (forming the mattress border assembly) and the sheets of foam.

[0012] In an alternate embodiment, double-sided adhesive tape strips may be applied to the end walls of the first and third foam rails, and to the portions of the side walls of the second and fourth foam rails to which the end walls of the first and third foam rails are to be adhered. The additional tape provides additional bonding strength.

[0013] A further aspect of the invention is a method of preparing a mattress border assembly for pre-assembly and shipment prior to assembly into a mattress construction. With such method, a strip or piece of double-faced adhesive tape is applied to at least a portion of an end wall of a first foam rail, wherein one face of said adhesive tape adheres to the end wall and the other face of the adhesive tape is covered with a removable liner. The first foam rail and a second foam rail may be shipped unassembled to a mattress fabricator. When the mattress border assembly is ready to be assembled together, the removable liner may be removed and the end wall of the foam rail may be attached to a portion of the side wall of a second foam rail with the exposed adhesive face of the adhesive tape. Similarly, a piece of double-faced adhesive tape may be applied to at least a portion of a top wall or a bottom wall of a foam rail, wherein one face of said adhesive tape adheres to the top wall (or bottom wall) and the other face of the adhesive tape is covered with a removable liner. In this manner, the mattress border assembly may be shipped in unassembled condition, as a series of separate foam rails, or other components or parts, with adhesive tape applied thereto. The frame-like mattress border assembly then may be assembled together by the mattress assembler as the mattress itself is being constructed. The pre-assembly with the adhesive tape avoids the problems inherent with liquid and hot melt adhesives. In addition, shipping costs are reduced because the foam rails can be more efficiently packed. Moreover, the foam rails are less likely to be damaged when shipped prior to assembly into a mattress border construction.

[0014] The invention comprises in yet another aspect a method for making a mattress border assembly by fixedly adhering together at least a portion of an end wall of a first foam rail to at least a portion of a side wall of a second foam rail with an adhesive tape. In the preferred embodiment, the end walls of the first and third foam rails are fixedly adhered to at least a portion of the side walls of the second and fourth foam rails to form a generally rectangular frame structure or mattress border assembly.

DESCRIPTION OF THE FIGURES

[0015]FIG. 1 is perspective view of a first side rail for a mattress border assembly showing adhesive tape applied to the end walls of the first side rail;

[0016]FIG. 2 is a cross-sectional view in elevation taken along line 2-2 of FIG. 1;

[0017]FIG. 3 is an end cross sectional view showing multiple side rails packed in a shipping carton wherein each side rail has a strip of double-sided adhesive tape applied to its end walls, with one surface of said strip covered by a removable protective liner;

[0018]FIG. 4 is an exploded perspective view of a mattress construction having a mattress border assembly according to the invention;

[0019]FIG. 5 is a top plan view of a mattress border assembly according to the invention;

[0020]FIG. 6 is a right side elevational view of the mattress border assembly of FIG. 5;

[0021]FIG. 7 is an exploded perspective view of a mattress border assembly according to the invention including upper and lower cover sheets;

[0022]FIG. 8 is a top plan view of the mattress border assembly of FIG. 7, partially broken away to show strips of adhesive tape applied on the side wall surfaces of the side rails and end rails; and

[0023]FIG. 9 is a right side elevational view of the mattress border assembly of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024] Referring first to FIGS. 1 and 2, a side rail 10 formed of a resilient material such as polyurethane foam has a top wall 12, a bottom wall 14, two side walls 16 and two end walls 18. The side rail 10 may be comprised of polyurethane foam surrounding springs or other firming central mattress structure, such as shown in U.S. Pat. No. 5,537,699, or latex core, or fiber core or water or air mattress, or the like. Strips of double-sided adhesive tape 20 are applied to each end wall 18. If the side rail 10 is intended for shipment to a mattress fabricator for later assembly, the exposed adhesive surfaces of the strips 20 are covered with a removable protective liner 22. FIG. 2 shows the adhesive 23 applied to each surface of the strip 20.

[0025] Ideally, the strips 20 of adhesive tape are pre-applied to multiple foam side rails 10 before the side rails are intended for assembly into a mattress border construction. The pre-assembled side rails 10 with a strip 20 of adhesive applied to each end wall 18 may be stacked in a shipping carton 24 for delivery to a mattress fabricator. Hence, as shown in FIG. 3, twelve side rails 10 may be stacked in a shipping carton 24 in pre-assembled form for later assembly into a mattress border assembly. Of course, it is also possible to ship end rails with pre-applied adhesive tape, or to include a combination of side rails and end rails in a single shipping carton. The strips 20 of double-sided adhesive tape are covered with liner 22 to prevent the side rails 10 from adhering to the carton 24 or other side rails.

[0026] As shown best in FIGS. 4 to 6, a mattress border assembly 30 comprises a frame-like structure formed from two side rails 10, 10′ adhered to two end rails 32, 32′. Each end rail 32, 32′ preferably is formed of polyurethane foam, but may be comprised of polyurethane foam surrounding a network of supporting springs or other firming structure, such as shown in U.S. Pat. No. 5,537,699, or the like. Each end rail has a top wall 34, a bottom wall 36, two side walls 40 and two end walls 38. A strip 20 of adhesive tape applied to a first end wall 18 of a first side rail 10 adheres to a portion of a side wall 40 of a first end rail 32. Concurrently, a strip 20 of adhesive tape applied to a second end wall 18′ of the first side rail 10 adheres to a portion of a side wall 40′ of a second end rail 32′. In like manner, a strip 20 of adhesive tape applied to a first end wall 18 of a second side rail 10′ adheres to a portion of a side wall 40 of a first end rail, and a strip 20 of adhesive tape applied to a second end wall 18′ of the second side rail 10′ adheres to a portion of a side wall 40′ of the second end rail 32′.

[0027] The adhesive tape must have sufficient bonding strength to adhere to the strands of a polyurethane foam network. We have found that the tape should have a bonding strength in the range of 5 to 15 psi, preferably 10 psi. The tape preferably is coated with an acrylic adhesive to a coating weight in the range of 30 to 34 grains per 24 square inches, preferably 32 grains per 24 square inches. The bond must tack and set quickly, reaching about 90% of its full bonding capability within about 10 minutes of adhering parts together with the tape, and preferably reaches full bonding capability within about 15 minutes. The bond also should hold securely such that a 100 g weighted material held to foam with such adhesive tape will remain secure for at least 10,000 minutes. Preferably, the double-sided adhesive tape is 3M #9695 tape.

[0028] Whereas a liquid adhesive or hot melt adhesive has ability to penetrate into the foam strand network to increase bonding sites and form a strong bond, the adhesive present on a strip of an adhesive tape does not penetrate the strands. Heretofore, adhesive tapes were not believed to have sufficient bonding strength to hold foam components together. Surprisingly, we have found that adhesive tapes with the above adhesive coating weigth, bonding strength and adhesive setting time, sometimes called dwell time, are able to hold foam components together so that tear strengths greater than about 15 psi are required to separate the foam components.

[0029] In one preferred embodiment, the strips 20 of adhesive tape are applied to portions of the end walls 18 of a side rail 10 so as to minimize the amount of adhesive tape and reduce costs. We have found that the strips should be applied at minimum to a portion of the end walls of the side rails that will be adjacent the outer edge of the mattress border assembly when the border assembly is fully assembled. Bonding along the outer edge of the mattress border encasement system efficiently maintains the durability and integrity of the system. We prefer to use adhesive tapes with a minimum width of two inches, although other widths may be suitable and perform effectively.

[0030] One advantage of the present invention is that the side rails 10 and end rails 32 may be shipped in a pre-assembled form with strips 20 of adhesive tape applied to their surfaces. One side of the double sided tape is applied to the rails by the foam fabricator, and the other side is covered with protective liner until such time as the rails are intended to be brought together to form a mattress border assembly. Such pre-assembly of mattress border assembly components for shipment prior to final assembly has not heretofore been possible with liquid adhesives and hot melt adhesives. Shipping the mattress border assembly as a fully-assembled construction is more costly because the mattress border assembly does not efficiently fill standard shipping cartons, but leaves a void space in the central portion bounded by the rails. By contrast, as shown in FIG. 3, shipping cartons can be efficiently packed with multiple side rails (or with end rails or a combination of side rails and end rails or other components) in stacked relation, without wasted space or volume within a shipping carton.

[0031]FIG. 7 shows a foam mattress core 50 surrounded by a mattress border assembly 60 according to another embodiment of the invention. In this embodiment, each side rail 10 and end rail 32 includes additional strips of adhesive tape.

[0032] As shown best in FIG. 7, a first end rail 10 has a top wall 12, a bottom wall 14, two side walls 16 and two end walls 18, 18′. A strip 20 of adhesive tape is applied to each end wall 18, 18′ just as in the embodiment shown in FIG. 5. In addition, an elongated strip 62 of double-sided adhesive tape is applied to the top wall 12, and an elongated strip 64 of double-sided adhesive tape is applied to the bottom wall 14 of the first end rail 10. Similarly, strips 62′ and 64′ are applied to the top wall 12′ and bottom wall 14′ of the second end rail 10′. A first end rail 32 has an elongated strip 66 of double-sided adhesive tape applied to the top wall 34, and an elongated strip 68 of double-sided adhesive tape applied to the bottom wall 36. Similarly, strips 66′ and 68′ are applied to the top wall 34′ and bottom wall 36′ of the second end rail 32′. In this preferred embodiment, the strips of adhesive tape are shown covering only a portion of the top walls and bottom walls of the end rails. While tape could be applied to cover the entire top and bottom wall surfaces of the side and end rails within the scope of this invention, it has been found that sufficient bonding is obtained by applying the strips to the portions nearest to what will become the outer perimeter of the mattress border assembly. With this preferred construction, less tape is required resulting in substantial material cost savings.

[0033] The strips 62, 64, 66, and 68 are covered with protective liner (not shown) as in the prior embodiment to permit the rails to be shipped in an unassembled form for assembly by a mattress fabricator. When the mattress is ready for assembly, the protective liners are removed first from the strips of adhesive covering the end walls 18, 18′ of the side rails 10, 10′. The end walls 18, 18′ are then adhered to portions of the side walls of the end rails 32, 32′ to form the mattress border assembly frame-like structure such as previously shown in FIG. 5.

[0034] Thereafter, the mattress core 50 is positioned within the frame-like structure. The mattress core 50 has been illustrated as a foam mattress, but might be any other mattress core structure known in the art, such as a network of springs within a casing or ticking material.

[0035] The protective liners are then removed from tape strips 62 and 66 to expose the adhesive surface of the strips on the top walls 12 of the side rails 10 and the top walls 34 of the end rails 32. A first foam sheet cover 70 is then adhered to the top walls 12, 34 by the adhesive tape.

[0036] The protective liners are then removed from tape strips 64 and 68 to expose the adhesive surface of the strips on the bottom walls 14 of the side rails 10 and the bottom walls 36 of the end rails 32. A second foam sheet cover 72 is then adhered to the bottom walls 14, 36 by the adhesive tape.

[0037] The mattress construction so formed comprises a mattress border assembly encasing a mattress core 50 as shown in FIGS. 8 and 9. Assembly is completed by the mattress fabricator without use of liquid adhesives or hot melt adhesives. The mattress border assembly components are fixedly adhered together using only the adhesive tape. The mattress construction can then be completed in the customary fashion, by encasing the assembly in a fabric or quilting or ticking to form the completed mattress.

[0038] The invention has been illustrated by detailed description and examples of the preferred embodiments. Various changes in form and detail will be within the skill of persons skilled in the art. Therefore, the invention must be measured by the claims and not by the description of the examples or the preferred embodiments. 

We claim:
 1. A border assembly for a mattress or bedding material, comprising: a first foam rail having a top wall, a bottom wall, a side wall and an end wall; a second foam rail having a top wall, a bottom wall, a side wall and an end wall; and a piece of adhesive tape applied to at least a portion of the end wall of the first foam rail so that said end wall may be fixedly adhered with said adhesive tape to at least a portion of the side wall of the second foam rail sleeve.
 2. The border assembly of claim 1, wherein the adhesive tape comprises a double-faced adhesive tape having a first face and a second face.
 3. The border assembly of claim 2, wherein the first face and the second face of the adhesive tape are each coated with adhesive to a coating weight of at least 30 grains per 24 square inches.
 4. The border assembly of claim 2, wherein the adhesive tape achieves a bonding strength of at least 5 psi when adhered to foam.
 5. The border assembly of claim 2, wherein the first face is adhered to the end wall and the second face is adhered to the side wall.
 6. The border assembly of claim 1, further comprising a second piece of adhesive tape applied to the portion of the side wall of the second foam rail sleeve so that the piece of adhesive tape applied to the portion of the end wall of the first foam rail fixedly adheres to the second piece of adhesive tape applied to the portion of the side wall of the second foam rail sleeve.
 7. The border assembly of claim 1, wherein the first foam rail has a second end wall and a second piece of adhesive tape is applied to at least a portion of the second end wall.
 8. The border assembly of claim 1, wherein a second piece of adhesive tape is applied to at least a portion of the top wall of the first foam rail.
 9. The border assembly of claim 1, wherein a second piece of adhesive tape is applied to at least a portion of the top wall of the second foam rail.
 10. The border assembly of claim 1, further comprising: a third foam rail having a top wall, a bottom wall, a side wall and an end wall; and a fourth foam rail having a top wall, a bottom wall, a side wall and an end wall, wherein a second piece of adhesive tape is applied to at least a portion of the end wall of the third foam rail so that said end wall may be fixedly adhered with said adhesive tape to at least a portion of the side wall of the fourth foam rail sleeve.
 11. The border assembly of claim 10, wherein the first foam rail has a second end wall and a third piece of adhesive tape is applied to at least a portion of the second end wall of the first foam rail so that said end wall may be fixedly adhered with said adhesive tape to at least a portion of the side wall of the fourth foam rail sleeve.
 12. The border assembly of claim 11, wherein the third foam rail has a second end wall and a third piece of adhesive tape is applied to at least a portion of the second end wall of the third foam rail so that said end wall may be fixedly adhered with said adhesive tape to at least a portion of the side wall of the second foam rail sleeve.
 13. The border assembly of claim 1, wherein a second piece of adhesive tape is applied along at least a portion of the top wall of the first foam rail so that the top wall may be fixedly adhered to a foam sheet or another component of a mattress with said adhesive tape.
 14. The border assembly of claim 13, wherein the second piece of adhesive tape is applied along the entire length of the top wall of the first foam rail.
 15. The border assembly of claim 13, wherein adhesive tape is applied to at least a portion of the top walls of each of the second, third and fourth foam rails.
 16. The border assembly of claim 13, wherein adhesive tape is applied to at least a portion of the bottom walls of each of the first, second, third and fourth foam rails so that the bottom walls may be fixedly adhered to a foam sheet or another component of a mattress with said adhesive tapes.
 17. A method of preparing a mattress border assembly for pre-assembly into a mattress construction, comprising: applying a piece of double-faced adhesive tape to at least a portion of an end wall of a foam rail, wherein a first face of said adhesive tape adheres to the end wall and a second face of the adhesive tape is covered with a removable liner.
 18. The method of claim 17, further comprising applying a second piece of double-faced adhesive tape to at least a portion of a top wall of a foam rail, wherein a first face of said second adhesive tape adheres to the top wall and the second face of the second adhesive tape is covered with a removable liner.
 19. A method for making a mattress border assembly, comprising: fixedly adhering together at least a portion of an end wall of a first foam rail to at least a portion of a side wall of a second foam rail with an adhesive tape.
 20. The method of claim 19, further comprising: fixedly adhering together at least a portion of a an end wall of a third foam rail to at least a portion of a side wall of a fourth foam rail with an adhesive tape.
 21. The method of claim 20, further comprising: fixedly adhering together at least a portion of a second end wall of the first foam rail to at least a portion of the side wall of the fourth foam rail with an adhesive tape.
 22. The method of claim 21, further comprising: fixedly adhering together at least a portion of a second end wall of the third foam rail to at least a portion of the side wall of the second foam rail with an adhesive tape.
 23. The method of claim 19, wherein the adhesive tape comprises a double-faced adhesive tape having a first face and a second face, the first face and the second face each having adhesive thereon to a coating weight of at least 30 grains per 24 square inches.
 24. The method of claim 19, further comprising joining the mattress border assembly to a body-supporting section of a mattress. 